محمد کاظم حفیظی author میر کاظم جلالی author text article 2001 per To interpret the gravity anomaly of a Koromite mine in south - west of Iran, we have used the three dimensional inversion problem. The method introduced by Last and Kubik (1983) and improved by Lewi (1997) for high precision gravity data has been tested to determine the 3-dimensional form of the anomaly. The results of the inversion process have been approved by exploration drill holes in the area recently. Institute of Geophysics, University of Tehran 2538-371X 27 v. 1 no. 2001 https://jesphys.ut.ac.ir/article_13318_fe3226c1d0999d9af475526dda50c2c9.pdf عباسعلی علی اکبری بیدختی author تاج الدین بنی هاشم author آرمین دهقان author text article 2001 per In this study, turbulent flow around a Guassian hill in a water tunnel is studied. Using a hot film anemometer, velocity and turbulent qualities (such as turbulence flux and intensity) is measured at different parts of the model. To understand these measurements, mean velocity deviation and perturbation velocity fluctuation contours, also turbulence flux and intensity profiles are presented and the results are consistent with those obtained by other investigators. Also the cavities in the downwind of the hill cause intense turbulence its scale being in order of cavities. The increase of velocity around the hill especially above the crest is significant. These studies in the use of optimum wind energy in hilly regions are useful. Institute of Geophysics, University of Tehran 2538-371X 27 v. 1 no. 2001 https://jesphys.ut.ac.ir/article_13319_0a13ecc4697057242ddffe20d39c6d13.pdf ولی کلانتر چاهوکی author مجید عباسپور author text article 2001 per A computer program was developed to predict the dispersion of gaseous pollutant in the atmosphere. This program relies on puff method, and in order to consider the wind shear effects, the program has the ability to consider the complete dynamic and unsteady atmospheric conditions. Plume rise of hot pollutants due to buoyancy effects was also considered. The program has the ability to perform the real-time calculations and uses on-line data of atmospheric conditions that are measured directly. In order to consider the effects of the presence of buildings and other obstacles or sudden changes in surface roughness by the dispersion of released materials, a model was added to evaluate the dispersion coefficients in the wake of obstacles. Using this relatively complete simulation, we analyzed the effects of the above parameters on the dispersion of gaseous pollutants in the atmosphere. Institute of Geophysics, University of Tehran 2538-371X 27 v. 1 no. 2001 https://jesphys.ut.ac.ir/article_13320_3f08c5743211be193e5abe2ab2940f95.pdf ابوالفضل مسلمی author حسن معصوم زاده author عبدالرحیم جواهریان author text article 2001 per One of the most important steps in the processing of VSP data is the separation of upcoming and down going waves. It can be performed by applying a velocity filter either in the f-k or 't-p domain. In the f-k domain, upcoming and down going waves will be separated into two groups having negative and positive wave numbers, respectively. A simple way of extracting them is to remove energies with the positive or negative velocities in the f-k plane. Similarly, by transforming VSP data from t-x domain to 't-p domain, upcoming and down going wave fields become separable and they are mapped to different quadrants of a 't-p plane. This allows either upcoming or down going waves to be reconstructed by the application of inverse Radon transform to the related quadrant of the 't-p plane. Results obtained by the 't-p method are similar to those obtained by the f-k velocity filtering. However, by implementing an amplitude ratio-resting filter in the forward slant stack, the quality of the reconstructed wave field would be improved. The filter was based on the amplitude of a slant-stacked event. The event with different amplitudes can be identified and suppressed when amplitudes are incoherent. In this regared, the efficiency of the f-k filter and the Radon transform over synthetic and real VSP data are considered. For the real data, we compared the results of our written soft wares with those of the Prom AX software. Institute of Geophysics, University of Tehran 2538-371X 27 v. 1 no. 2001 https://jesphys.ut.ac.ir/article_13321_7f062a7522884cd3aa9eb1c40f755618.pdf وحید ابراهیم زاده اردستانی author text article 2001 per To interpret the gravity anomaly of a Koromite mine in south - west of Iran, we have used the three dimensional inversion problem. The method introduced by Last and Kubik (1983) and improved by Lewi (1997) for high precision gravity data has been tested to determine the 3-dimensional form of the anomaly. The results of the inversion process have been approved by exploration drill holes in the area recently. Institute of Geophysics, University of Tehran 2538-371X 27 v. 1 no. 2001 https://jesphys.ut.ac.ir/article_13322_e9fb97e90c153fc5b6e6157105ab10fd.pdf حجت ا... رنجبر author مصطفی شاه حسینی author ماه بانو تاتا author text article 2001 per This paper describes a methodology for the integrated interpretation of airborne magnetic and airborne y-ray spectrometer data. The Darrehzar porphyry copper deposit is situated in the Uromieh-Dokhtar magmatic assemblage of Central Iran. Phyllic and propylitic alteration are pervasive in the area but potassic and argillic alterations are not readily recognized on the surface. The spatial distributions of geophysical data resemble the lithological and alteration patterns in the area. The Darrehzar porphyry copper deposit is considered as a control site for determination of the degree that the geophysical data is correlated with the mineralization zone. Airborne magnetic/radiometric, geochemical /alteration and ground geophysical data sets have been integrated and analyzed using canonical correlation method. This technique is found to be useful for the delineation of hydrothermally altered areas and data compression. Institute of Geophysics, University of Tehran 2538-371X 27 v. 1 no. 2001 https://jesphys.ut.ac.ir/article_13323_2ac05eeb337b40a140bfb98e13dc1eaf.pdf آفتاب عالم خان author سید همایون اختر author text article 2001 per Institute of Geophysics, University of Tehran 2538-371X 27 v. 1 no. 2001 https://jesphys.ut.ac.ir/article_13324_49f5585076624910c4128360cc847740.pdf سوشائولان author جوچوان جن author وو جونگ لیانگ author text article 2001 per We analyzed the International Seismological Center (ISC) catalogue of seismological publications from 1980 to 1995 to investigate to what extent the information provided by an earthquake has been utilized to obtain a better understanding of earthquakes and seismic disaster. We select the ISC bulletin which has a wider coverage of seismological journals and languages than the Scientific Citation Index (SCI), so that there is less regional or language bias in the analysis. The earthquakes in the catalogue spans the period from 1975 to 1990. Papers which have direct relations with an earthquake as defined by the ISC catalogue ranges from 1 to 102 in order of magnitudes. The logarithm of the maximum number of papers on an earthquake is shown to be proportional to the magnitude of the earthquake, which provides a possibility to define a 'normalized impact factor' of an earthquake, so that earthquakes with different magnitudes can be compared with each other. The magnitude span of earthquakes with a certain 'impact factor' and the 'impact factor' itself can be used in the regional comparisons. The analysis shows a regional difference that the academic impact strength' of the earthquakes occurring in Asian developing countries are not comparable to the societal effects of these earthquakes, implying that one of the future directions of the development of Asian seismology is to have more observations and more researches on the earthquakes occurred 'at home. Institute of Geophysics, University of Tehran 2538-371X 27 v. 1 no. 2001 https://jesphys.ut.ac.ir/article_13325_4a341acf6b2bdb94e71cd7b99235f1ea.pdf